This invention relates to embroidery hoops for embroidering fabric and more particularly to a hoop that increases the "bite" on the fabric as the fabric is pulled or pressed in the hoop, regardless of which side of the hoop the fabric is stretched across.
Embroidery hoops of the prior art have traditionally comprised concentric inner and outer rings, with the diameter of the outer ring adjustable to fit it snugly against the inner ring. To mount fabric to the hoop, the fabric is slipped between the outer and inner rings and pulled taut to form a drum-like surface. The outer ring is then tightened to hold the fabric under tension. Embroidery is performed by pressing a needle and thread through the taut fabric.
The rings of most hoops on the market, such as disclosed in U.S. Pat. No. 3,818,620 to Field et al., have smooth abutting surfaces between which the fabric passes. Pulling and pressing on the fabric while embroidering causes the rings to slide relative to one another, weakening the bite of the hoop on the fabric and allowing it to slip between the rings and slacken.
Recognizing this problem, several attempts have been made to strengthen the hoop's grip on the fabric by mounting a lip on the inner ring extending radially outward to overlie the upper surface of the outer ring. U.S. Pat. No. 2,957,269 to Nohl et al. shows such an embroidery hoop. The fabric is laid on the upper side of the outer ring, and the inner ring is then pressed down over the fabric as far as the lip allows. So long as the fabric is pressed only on its upper surface, the lip tends to press against the outer ring to keep the rings together. However, the lip is ineffective if the fabric is pressed on its lower surface. The lip also fails to urge the rings together if an attempt is made to pull the fabric taut.
U.S. Pat. No. 3,906,647 to Bates, Jr., uses a structure similar to that of Nohl et al. but mounts the fabric to the hoop in a different manner. Bates applies the fabric over the lip of the inner ring and then between the contiguous rings. Pulling on the fabric when mounted in this arrangement urges the two rings together. But Bates, like Nohl, is effective against pressure only on one surface of the fabric. Pressing against the lower fabric surface still tends to separate the rings. Both devices thus require the user to insert the fabric in a unique way and to embroider on a specific surface.
Another drawback of prior hoops is their instability. The hoop is held in one hand while the needle is pressed against the fabric with the other. A hand supporting a small portion of the hoop, however, cannot prevent the hoop from turning under the pressure of the other hand.